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Abstract  

An investigation of the influence of some experimental parameters on thermochromatographic separations has been carried out. It is shown that the position of the deposition zone depends on separation time, purity of the inert gas, and on type and amount of the chlorinating agent. The gas flow rate and the amount of the transported compounds have no influence within the limits of experimental conditions. From the experimental results it can be concluded that in some cases the deposited compounds react with the surface or with the excess gas.

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Abstract  

The use of phase change materials (PCMs) in thermal storage is not a new concept, but engineers are continually finding new ways to utilize them in a wide range of applications. A PCM takes advantage of high latent heat in the phase change process to store large amounts of heat while undergoing only a small change in temperature. This property makes PCMs suitable for thermal storage purposes in a wide range of engineering applications. Due to the nature of these applications, it is vital to have a precise knowledge of the thermal characteristics of any PCM. Unfortunately, due to the low thermal conductivities and high latent heats found in PCMs, current measuring tools such as differential scanning calorimetry, provide inconsistent results. This paper conjectures that these errors come from the effects of low thermal diffusivity samples as well as improper data analysis methods.

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to the product of the entropy change, Δ S , and the temperature gradient, Δ T , which is the difference between the thermodynamic temperature gradient (associated with transformation) and the heat-imposed gradient at the reaction interface as a

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temperature organs or gradient chambers. As such a temperature gradient chamber (TGC) the authors built two wooden boxes, which were placed one above the other. The lower chamber was divided into two compartments by a wooden wall. The first compartment housed

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charging rate increases. Meanwhile, the temperature gradient in axial direction ( z ) increases remarkably with charging rate increase. The higher the charging rate, the larger the temperature gradient is. The maximum surface temperature is up to 60.99 °C

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Journal of Thermal Analysis and Calorimetry
Authors: Mark S. Romano, Sanjeev Gambhir, Joselito M. Razal, Adrian Gestos, Gordon G. Wallace, and Jun Chen

electrolyte, i.e. for systems using reversible redox couples, is given by , where K is the thermal conductivity of the electrolyte, A is the cross sectional area of each electrode and is the temperature gradient across the distance between the two

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Abstract  

Starting from tabulated thermodynamic data of stable compounds in the Mo−O−Cl system, phase diagrams for the Mo−O−Cl system were developed on the basis of GIBBS' phase law by means of thermodynamic calculations. The behaviour of molybdenum trioxide in a temperature gradient tube was investigated experimentally under chlorinating conditions, using99Mo as indicator. The thermochromatografically separated compounds were characterized by their deposition temperature in the temperature gradient tube and by an activation analytical determination of their Mo/Cl ratio. The experimental results were compared with the calculated phase diagram.

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Abstract  

Differential scanning calorimetry (DSC) is applied to analyse the process of ice melting. Experimental results were compared to those obtained by a numerical simulation in which a conventional enthalpy formulation was applied. The effects of various parameters on the kinetics of transformations and therefore the shape of curves has been analysed and the importance of temperature gradients inside the sample evaluated.

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Abstract  

An application of the temperature gradient tube method is described, which has allowed to chemically separate the elements, Be, Ca, Sc, Ti, V, Cr, Mn produced in an iron target irradiated by high energy protons, without noticeable contamination by natural impurities. It is suggested that this method could be useful in other works on small quantities of stable isotopes.

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